Decoration panels are widely used on both sides of windows, peripheries of room walls or furniture. Such decoration panels are fixed on the walls adjacent to the windows or the furniture by way of screws. But the windows or furniture are made in various sizes depending on their location, therefore the decoration panels must also be made in various sizes corresponding to the sizes of walls, windows or furniture. That is, a decoration panel of single size can not be used for all walls, windows or furniture. Therefore, the panel makers must prepare many apparatuses or moulds to meet the various sizes of decoration panels, which will result in high cost of manufacturing.